1. Field of the Invention
The present invention relates to an electronic musical instrument capable of generating a rhythm tone with a melody tone.
2. Prior Art
Conventionally, several kinds of electronic musical instruments capable of generating a rhythm tone are known. Among them, a first conventional electronic musical instrument capable of carrying out an automatic rhythm performance provides a rhythm tone source for generating rhythm tone signals of rhythm instruments such as a bass drum, snare drum, cymbal etc. and it also provides a rhythm pattern memory for storing rhythm pattern information indicative of rhythm patterns such as waltz, rumba, march etc. Next, a second conventional electronic musical instrument provides rhythm tone designating means called a "pad" in addition to the above-mentioned function of carrying out the automatic rhythm performance. By beating this pad the corresponding rhythm tones are generated. This kind of electronic musical instrument is disclosed in Japanese Utility Model Publication No. 59-18471, for example. As a further example of the foregoing second conventional electronic musical instrument, Japanese Patent Laid-Open Publication No. 1-177090 is known. Herein, kinds of tone of the percussion instruments such as hi-hat cymbal, bass drum and triangle can be programmed to the pads. As described above, the conventional electronic musical instrument can sound the percussion instrument tones by operating the pad. However, it cannot sound a musical tone to which an unconventional musical effect is applied (for example, sounds such as a siren sound, wave sound, drum roll, explosive sounds, etc.; hereinafter, such unconventional tones are simply referred to as "effected tone") by the pad operation. Further, a third conventional electronic musical instrument with a so-called "hold-mode function" can hold musical tone information when musical tones are generated by the operation of the pad or keyboard. Therefore, this third conventional electronic musical instrument can continue to generate the musical ton after the operation of the pad or keyboard is off.
However, in the case where the musical tone to be generated is the attenuating tone (or damping tone), the above-mentioned third conventional electronic musical instrument with the hold-mode function must attenuate its musical tone in accordance with the predetermined envelope waveform. For this reason, there is a problem in that the tone-generation cannot be continued even if the musical tone information is held for an extended period of time.